Probe-sample interactions in reflection near-field scanning optical microscopy

Reflection near-field scanning optical microscopy with an asymmetric detector orientation is demonstrated. The effects of the probe-sample interactions are studied for different polarizations, detector orientations, and sample reflectivity. It is shown that the orientation of the detector can introduce shadowing in the images, which is opposite from the naive interpretation and which is dependent on the optical properties of the sample. Near-field optical images of metallic test patterns in reflection are shown that exhibit a lateral resolution of 40 nm.